Are you sure all your users have emails? I would pop a console.log(this.props.user) above those <td> elements and make sure your user objects are populated as you expect. The error is pretty clearly showing that emails is not a property on your user object in this case.

I found out that with the autopublish you only have access to certain user properties. When removing autopublish and creating publish & subscribe you get access to these other fields in the users collection!